MANIPULATION OF GVL/GVH REACTIONS IN ALLOGENEIC BMT

异基因骨髓移植被认为是治疗 白血病，部分通过免疫活性供体细胞的作用。 的 同种异体BMT的抗白血病或“移植物抗白血病（GVL）效应是一种免疫抑制剂。 抗肿瘤疾病免疫反应性的戏剧性例子， 以及成功使用同种异体骨髓移植治疗 恶性肿瘤证明有必要进行彻底的分析，以了解和 操纵反应。 GVL效应通常与以下因素相关： 移植物抗宿主病（GVHD），但GVL之间的确切关系 反应和临床GVHD是有争议的。 有临床和 GVL反应独立于GVHD的实验证据。 小鼠模型和体外技术提供了一个框架， 概念化和研究GVH和GVL反应之间的动态平衡 在本修订提案中，我们力求评估各种方法， 使用可以很容易地 在白血病患者中完成。 本研究的最终目标是 (i)开发和测试治疗白血病宿主的策略， 实现长期生存和（ii）提高安全性和有效性 BMT使更多的患者能够得到成功治疗。 实现这些 目标，建立良好的同种异体BMT小鼠模型将用于 降低GVH反应性而不损失GVL的试验策略 在必要时，可以提高GVL反应性而不发生GVHD。 我们 提出测试三个主要假设：（1）选择性离体 骨髓接种物中T细胞亚群的耗竭可显著改善 异基因骨髓移植后的长期无白血病生存率;（2）GVH 可以在体内调节反应性而不损失GVL效应， 同种异体骨髓移植后给予单克隆抗体;（3）无效的GVL 白细胞介素-2 + CD 8 + T细胞可增强反应， 输注供体淋巴细胞，或给予免疫增强剂 抗CD 3单抗剂量。 三种小鼠异基因BMT模型， 供体和宿主之间不同程度的免疫遗传差异将是 采用 供体嵌合体的动力学和程度将通过流式细胞仪进行评估。 细胞计数分析。 分子探针将用于监测 白血病的持续性沿着生物测定。 各种预- 和骨髓移植后干预对发展供者-宿主耐受性的影响 BMT嵌合体将使用体外和体内组合测定。 分析，包括有限稀释分析。 拟议的研究将 有助于确定值得进一步评价的策略和试剂， 临床BMT以及在使用前需要修改的那些。

Allogeneic bone marrow transplantation is thought to be curative in leukemia, in part, through the action of immunocompetent donor cells. The antileukemia or "graft-vs-leukemia (GVL) effect of allogeneic BMT is a dramatic example of immunological reactivity against neoplastic disease, and the potential benefit from successful use of allogeneic BMT to treat malignancy justifies a thorough analysis in order to understand and manipulate the reaction. The GVL effect usually occurs in association with graft-vs-host disease (GVHD), but the precise relationship between the GVL reaction and clinical GVHD is controversial. There is clinical and experimental evidence for a GVL reaction that is independent of GVHD. Murine models and in vitro techniques provide a framework in which to conceptualize and study the dynamic balance between GVH and GVL reactions in man. In this revised proposal, we seek to evaluate methods to manipulate these reactions using strategies that can be readily accomplished in leukemia patients. The ultimate goals of this research are (i) to develop and test strategies for curing leukemic hosts while achieving long-term survival and (ii) to improve the safety and efficacy of BMT so that more patients can be treated successfully. To achieve these goals, well established murine models of allogeneic BMT will be used to test strategies for decreasing GVH reactivity without loss of the GVL effect and increasing GVL reactivity without GVHD when necessary. We propose to test three major hypotheses: (1) that selective ex vivo depletion of T-cell subsets in the BM inoculum can significantly improve long-term, leukemia-free survival after allogeneic BMT; (2) that GVH reactivity can be regulated in vivo without loss of the GVL effect using MoAbs administered after allogeneic BMT; and (3) that an ineffectual GVL reaction can be enhanced by interleukin-2 + CD8+ T-cells, by delayed infusion of donor lymphocytes, or by administration of immunoenhancing doses of anti-CD3 MoAb. Three murine models of allogeneic BMT with differing degrees of immunogenetic disparity between donor and host will be used. The kinetics and extent of donor chimerism will be assessed by flow cytometric analysis. Molecular probes will be used to monitor the persistence of leukemia along with bioassays. The effect of various pre- and post-BMT interventions on the development of donor-host-tolerance in BMT chimeras will be determined using a combination of in vitro and in vivo assays, including limiting dilution analysis. The proposed studies will help identify strategies and reagents that merit further evaluation in clinical BMT as well as those that require modification before use.